InstallBuilder for Qt Windows (versions prior to 20.7.0) installers look for plugins at a predictable location at initialization time, writable by non-admin users. While those plugins are not required, they are loaded if present, which could allow an attacker to plant a malicious library which could result in code execution with the security scope of the installer.

InstallBuilder Qt installers built with versions previous to 22.10 try to load DLLs from the installer binary parent directory when displaying popups. This may allow an attacker to plant a malicious DLL in the installer parent directory to allow executing code with the privileges of the installer (when the popup triggers the loading of the library). Exploiting these type of vulnerabilities generally require that an attacker has access to a vulnerable machine to plant the malicious DLL.